/* nag_lapacklin_zppsv (f07gnc) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.3, 2024.
*/
#include <nag.h>
#include <stdio.h>
int main(void) {
/* Scalars */
Integer exit_status = 0, i, j, n, nrhs, pdb;
/* Arrays */
Complex *ap = 0, *b = 0;
char nag_enum_arg[40];
/* Nag Types */
NagError fail;
Nag_OrderType order;
Nag_UploType uplo;
INIT_FAIL(fail);
#ifdef NAG_COLUMN_MAJOR
#define A_UPPER(I, J) ap[J * (J - 1) / 2 + I - 1]
#define A_LOWER(I, J) ap[(2 * n - J) * (J - 1) / 2 + I - 1]
#define B(I, J) b[(J - 1) * pdb + I - 1]
order = Nag_ColMajor;
#else
#define A_LOWER(I, J) ap[I * (I - 1) / 2 + J - 1]
#define A_UPPER(I, J) ap[(2 * n - I) * (I - 1) / 2 + J - 1]
#define B(I, J) b[(I - 1) * pdb + J - 1]
order = Nag_RowMajor;
#endif
printf("nag_lapacklin_zppsv (f07gnc) Example Program Results\n\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &n, &nrhs);
if (n < 0 || nrhs < 0) {
printf("Invalid n or nrhs\n");
exit_status = 1;
goto END;
}
scanf(" %39s%*[^\n]", nag_enum_arg);
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
uplo = (Nag_UploType)nag_enum_name_to_value(nag_enum_arg);
/* Allocate memory */
if (!(ap = NAG_ALLOC(n * (n + 1) / 2, Complex)) ||
!(b = NAG_ALLOC(n, Complex))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
#ifdef NAG_COLUMN_MAJOR
pdb = n;
#else
pdb = nrhs;
#endif
/* Read the upper or lower triangular part of the matrix A from data file */
if (uplo == Nag_Upper)
for (i = 1; i <= n; ++i)
for (j = i; j <= n; ++j)
scanf(" ( %lf , %lf )", &A_UPPER(i, j).re, &A_UPPER(i, j).im);
else if (uplo == Nag_Lower)
for (i = 1; i <= n; ++i)
for (j = 1; j <= i; ++j)
scanf(" ( %lf , %lf )", &A_LOWER(i, j).re, &A_LOWER(i, j).im);
scanf("%*[^\n]");
/* Read b from data file */
for (i = 1; i <= n; ++i)
for (j = 1; j <= nrhs; ++j)
scanf(" ( %lf , %lf )", &B(i, j).re, &B(i, j).im);
scanf("%*[^\n]");
/* Solve the equations Ax = b for x using nag_lapacklin_zppsv (f07gnc). */
nag_lapacklin_zppsv(order, uplo, n, nrhs, ap, b, pdb, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapacklin_zppsv (f07gnc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* Print solution */
printf("Solution\n");
for (i = 1; i <= n; ++i) {
for (j = 1; j <= nrhs; ++j)
printf("(%7.4f, %7.4f)%s", B(i, j).re, B(i, j).im,
j % 4 == 0 ? "\n" : " ");
printf("\n");
}
/* Print details of factorization using
* nag_file_print_matrix_complex_packed_comp (x04ddc).
*/
printf("\n");
fflush(stdout);
nag_file_print_matrix_complex_packed_comp(
order, uplo, Nag_NonUnitDiag, n, ap, Nag_BracketForm, "%7.4f",
"Cholesky factor", Nag_IntegerLabels, 0, Nag_IntegerLabels, 0, 80, 0, 0,
&fail);
if (fail.code != NE_NOERROR) {
printf(
"Error from nag_file_print_matrix_complex_packed_comp (x04ddc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
END:
NAG_FREE(ap);
NAG_FREE(b);
return exit_status;
}
#undef A_UPPER
#undef A_LOWER
#undef B